Hi, here's the left Mei Kanji : 貮ツ胴梅沢文左衛門切落文正兀(花押)
The reading is " Futatsu Do Umezawa Bunzaemon Kiriotoshi Bunsho Kotsu(or Gotsu) (Kao)".
Bunsho is a Japanese nengo 1466-1467 and the last Kanji 兀 is a bit tricky.. I thought it was 18 一八 but Bunsho era only lasted for two years. Anyway 兀 means "high, stillness, cutting legs off etc (??).
http://kanji.jitenon.jp/kanjig/3147.html
There are two eras written on this Nakago.. maybe this Mei could have been carved later.
Hope this will help a bit.
Kay M